Leonardo De Castro
Javascript Developer
São Paulo, Brazil
Summary
👤
Senior🎓
Top SchoolLeonardo De Castro is a senior JavaScript developer from São Paulo with over a decade of experience building scalable, high-performance web applications and microfrontend architectures. He has a strong track record delivering production systems for enterprises like Pinterest and Blue Yonder, including migrations (npm→pnpm), sandboxed micro-frontends, and robust E2E testing that reduced flakiness across CI/CD. Comfortable across the full stack, he regularly crafts responsive component libraries, integrates CMS-driven workflows, and architects Node.js microservices to replace legacy monoliths. His work spans startups and large organizations—from launching an AI-powered SEO platform to shipping medical imaging tools—demonstrating both product-oriented thinking and technical rigor. Notably, he blends hands-on implementation with experiment-driven product improvements (conversion modules and advertiser experiments) to drive measurable adoption. Fluent in modern JS tooling (TypeScript, Next.js, React, Turborepo, pnpm) and cloud-native delivery, he pairs pragmatic engineering with a keen eye for UX and maintainability.
10 years of coding experience
7 years of employment as a software developer
Computer Technician, Software development, Computer Technician, Software development at Colégio Técnico ETEP
Portuguese, English, Spanish
Stackoverflow
11reputation
3kreached
1answer
2questions
Github Skills (39)
css10
javascript9
build-configuration9
commonjs9
html9
compiler8
react8
android8
typescript8
testing8
react-native7
zero-configuration7
ios7
frontend7
dicom6
Programming languages (3)
Github contributions (5)
leonardosarmentocastro/the-owl
Apr 2019 - Feb 2021
Enforce functional tests development by earning something tangible from it.
Contributions:91 commits, 3 PRs, 78 pushes in 1 year 10 months
testingenforceearningfunctional-tests
leonardosarmentocastro/cna
Aug 2022 - Jun 2024
Contributions:109 pushes, 1 branch, 49 tags in 1 year 11 months
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